Quadratic Equation help?

Discussion in 'Math' started by Khalid Abur-Rahman, Feb 11, 2009.

  1. Khalid Abur-Rahman

    Thread Starter Active Member

    Dec 25, 2008
    Can someone show me how to put this equation into quadratic forum?

    its specifaclly for JFET design by the way (Common Source Amplifier)

    A(v) = -(20k||R(d)/3k-R(d)+350=-4

    where k is for kilo ohms..

    how do I put it in quadratic form?

    Can you show me step by step?
  2. studiot

    AAC Fanatic!

    Nov 9, 2007
    I am not sure where the -4 comes in, is this the numerical value of the amplifcation?

    \frac{20000*Rd}{20000+Rd} * \frac{-1}{3000-Rd+350}

    If you multiply out the fractions you will get your quadratic in Rd. You should be able to carry on.

    Perhaps if you set this equal to -4 you will be able solve for Rd.
  3. nene biggie

    New Member

    Feb 28, 2009
    simplify to the simplest form then amply the quadratic formular ie x=-b+/-√b-4ac all over 2a